The goal of this proposal is to develop a miniaturized Left Ventricular Assist Device (LVAD) that is small enough to be placed in the thoracic cavity at the apex of the heart. The miniature pump is based on the Tesla principal and will be supported passively with conical hydrodynamic bearings, thus greatly reducing the pump size compared to previous Tesla pump designs. The final clinical system will consist of the implanted pump, controller with battery, and transcutaneous energy transmission coil. It will be a completely implantable system allowing the patient a near normal life style A passively suspended first generation Tesla type LVAD has been designed and tested in vitro and in vivo, demonstrating flows above 12 L/min with 90 mmHg pressure rise and low hemolysis levels. However, the device is large compared to current contemporary LVADs. The following specific aims are to be accomplished in this Phase 1 SBIR: 1) Use CFD and FEA studies to improve the motor design and system efficiency, minimize fluid stresses and minimize system size. These studies specifically will include optimization of conical hydrodynamic thrust bearings capable of supporting both axial and radial loads;2) Complete the design and manufacture of the miniature Tesla pump employing the conical hydrodynamic bearing;3) Adaptation of an inlet pressure sensor and controller to the miniature Tesla pump;and 4) Performance test (HQ) the miniature Tesla pump and perform initial hemolysis testing. This proposed research is intended to demonstrate that a miniaturized Tesla pump can be manufactured and that the pressure flow relationship and low rate of hemolysis of the larger device are maintained or improved. In addition, a pressure sensor that has been developed for the larger system can be incorporated in the miniature Tesla, thereby providing a means for implementing suction control.